The present invention relates in general to a safety system for airports and airfields and more particularly to an apparatus and method for installing a synthetic turf system around airport runways and taxiways to enhance and improve airport and airfield safety.
Airfields, including military airfields, small airfields and large commercial airports presently have grass surfaces adjacent to the airport runways and taxiways. Those natural grass surfaces are difficult, time consuming and expensive to maintain and are not aesthetically pleasing. More importantly, the existing grass surfaces create potential safety problems for departing and arriving aircraft. The existing grass surfaces also create potential safety problems relating to the clean-up of hazardous waste spills and to the use of pesticides and herbicides necessary for proper upkeep of the grass.
A further problem with natural grass surfaces at airports or airfields is improper water drainage. In typical natural grass installations, the surface of the soil is approximately at the same height as the concrete (or other) surface of a runway/taxiway. The height of the grass thus normally extends past the height of the runway/taxiway surface. Grass clippings, dust, dirt and debris blown across the runway/taxiway, catch the overextending lip of grass and collect adjacent thereto, creating a more extensive vertical barrier. The clippings, dust, dirt and debris trapped adjacent to the runway/taxiway increase the potential of “foreign object damage” or “FOD” to airplanes and are therefore classified as “FODS.” FODS are any foreign object that can damage a stationary or moving aircraft, specifically including a turbine engine.
The collected clippings, dust, dirt and debris along the edge of the runway/taxiway also inhibit proper water drainage from runways or taxiways. That build-up also traps and pools rainwater that contacts the runway/taxiway and drains to their sides (i.e., down their grade). The water eventually drains into and through the build-up and often creates a three to four foot (30 to 40 cm) area of wet mud adjacent to the runway. The grass in that area often dies, the mud dries and the top soil erodes so that new grass seed cannot effectively form a root system. Grass sod directly adjacent to a runway/taxiway can become loose, fly up and become a FOD, so that airports are effectively stuck with eroded soil in safety areas adjacent runways or taxiways.
Commercial airports (and certain other airports) provided graded surfaces to aid in draining heavy rains. Over time, the flow of water carrying dirt and debris away from the runway/taxiway erodes the grade, at least at certain points, in the natural grass surfaces adjacent to the runway/taxiway. Water tends to pool in such areas of the natural grass where the grade is eroded. The pooled water also kills the grass and creates muddy areas where little grows. The muddy areas are aesthetically displeasing and conventional vehicles such as sanitation trucks, maintenance trucks and emergency vehicles cannot travel on or over the muddy areas, if necessary.
In dry, desert like climates, sand adjacent to runways and taxiways also creates problems. Little grows in sand, which leaves the airport with the unenviable choice of either planting, irrigating and maintaining an expansive and expensive natural grass surface or exposing large areas of aesthetically displeasing sand. Conventional vehicles such as sanitation trucks, maintenance trucks and emergency vehicles also cannot travel on or over the areas having sand, if necessary. Windblown sand can also be a dangerous FOD, which in certain instances has been known to sand blast the inside of a jet's turbine engine.
Natural grass is also expensive to upkeep. In peak periods, some airport operators must mow twice a week. Weeds, high grass, muddy areas and other obstructions collect litter and debris intermittently over the entire airport or airfield.
Although airfields are noisy and frequented by large, fast moving jet-powered aircraft, they still tend to support wildlife. Airfields often cover large expanses of open natural grass field surrounded by fences, providing good visibility and a haven for birds and other animals from man and pets. Man-made retention basins and drainage ditches provide a convenient source of free standing water. Mowing machines leave behind mowed straw and the like for nest construction and shattered seeds and maimed insects for food.
The water and nesting materials lead to a well known and potentially dangerous safety problem, bird and animal strikes. Many birds including gulls, waterfowl, raptors such as hawks and other species flock to airfields to eat, drink and reproduce. Birds eat insects and grubs which live in natural grass up to six inches (15 cm) below the soil surface. Birds also eat rodents, which feed on the insects. Standing water, especially after fresh rains, attracts many species of birds, including waterfowl. Large birds such as ducks or geese also create especially dangerous conditions for aircraft and are classified as FODs. Natural grass further provides materials and cover for birds to nest and breed. Accordingly, many airports and airfields report collisions between airplanes and birds and other animals.
Runway incursions present another significant safety problem for airports and airfields. The Federal Aviation Administration (“FAA”) defines a “runway incursion” as, “any occurrence at an airport involving an aircraft, vehicle, person, or object on the ground that creates a collision hazard or results in loss of separation with an aircraft taking off or intending to take off, landing, or intending to land.” A “collision hazard” is defined as any “condition, event or circumstance which could induce an occurrence of a condition or surface accident or incident (e.g., a pilot takes an unplanned or evasive action to avoid an aircraft, vehicle, object, or person on the runway).” “Loss of separation” includes “an occurrence or operation, which results in less than the prescribed separation between aircraft, vehicles, or objects.” For definitions, see:
http://www.faa.gov/runwaysafety/, under statistics and data.
The FAA places runway incursions into three general causal categories, namely: (i) a pilot can cause a pilot deviation (“PD”); (ii) a tower controller can cause an operational error (“OE”) runway incursion; and (iii) a person or vehicle on a runway/taxiway can cause a vehicle/pedestrian device (“V/PD”) runway incursion. Runway incursions have led to serious accidents.
One cause of the problem is that the complex instrument panels in many airplanes cause pilots to be “heads down” for substantial periods of time. When a pilot is “heads down” it is more difficult for the pilot to know the plane's exact position on the runway/taxiway. Moreover, when pilots do look out their windows, airport markings should be clean and legible. Pilots should be able to taxi to and from an active runway without getting lost.
Presently, the pavement markings and small upright runway signs placed near runways and taxiways provide limited guidance to pilots, ground crews and tower controllers. The pavement signs fade and chip and do not contrast well against gray pavement. The upright signs are necessarily small, so that pilots, grounds people and tower personnel can have an uninterrupted view of other ground and air vehicles on intersecting and adjacent runways and taxiways.
A need exists for a solution to each of the above-described airport safety problems.